The present invention relates to a microstructure, and particularly a device with a pair of parallel conductive plates that may be employed as a detector, a signal filter, or a passive device, and methods of manufacturing the same.
Many nano-scale devices require a pair of conductive plates having a small separation distance. Such nano-scale devices include a detector, a passive device, or a signal filter. For example, the detector may be a particle detector, a pH detector, a fire alarm, or any other type of device configured to detect change of the composition of the material between a pair of conductive plates. The passive device may be a capacitor, an inductor, or a combination thereof. The signal filter is a set of electronic devices including at least one capacitor or inductor that is configured to provide a signal filtering function.
Such nano-scale devices require a small separation distance between the pair of conductive plates. For example, a capacitor requires a small separation distance to increase the capacitance. A detector requires a small distance to maximize the change in the detected signal.
Control of the separation distance between a pair of conductive plates is limited by available manufacturing methods. Typically, the limitation on the separation distance is imposed by the smallest dimension that available lithography tools can print. Despite continuing progress in lithographic technology, the critical dimension, i.e., the smallest dimension that a lithographic tool may print, is about 40 nm as of 2009. Reducing the separation distance to a dimension less than the critical dimension faces difficulties.